Reinforced rifle stock

ABSTRACT

A rifle stock is configured to receive a barreled action having an attached barrel and a lower surface which also has a downward protrusion. A shell having an exterior surface defines an exterior and an interior of the stock. The shell has opposed sidewalls extending from a bottom portion and an intermediate portion. A span element which is preferably a planar element and at least in part encompassed by fill material spans between the opposed sidewalls. The span includes a structural element that connects to the shell, a transverse intermediate portion, vertical end portions, and a forward edge for a protrusion receptacle which is defined in part by fill material in the stock and in part by the span element. The protrusion receptacle receives a downward extending protrusion of the rifle action. The fill may comprise rigid foam, composite materials, carbon fiber, or combinations of these materials.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 63/231,781, filed on Aug. 11, 2021, entitled “CompositeStock Recoil Load Shelf,” which is hereby incorporated by reference inits entirety for all that is taught and disclosed therein.

FIELD OF THE INVENTION

The present invention relates to stocks for shoulder-fired firearms.

BACKGROUND AND SUMMARY

Rifle stocks enable a shooter to comfortably and securely support afirearm so that a shooter may point the rifle at an intended target.Traditional rifle stocks offer a stable and unyielding platform so thatwhile collecting recoil force while the bullet is being expelled throughthe rifle barrel, the shooter is able to maintain a preferred alignmentof the barrel axis with respect to a desired trajectory once the bulletleaves the barrel.

Rifle stocks are also designed to transfer the impulses from thecombustion and propulsive events to the supporting elements of theshooter's body; mostly to the shoulder but also in part through theshooter's hands and arms, especially if the stock includes a sling.

In many shooting sports and in tactical and military uses a primaryunwanted element in rifle stocks is weight, and so a primary objectiveof the invention is to provide a rifle stock offering desirable rigiditywhile having the least amount of mass in unnecessary areas wherematerial does not contribute substantially to structural rigidity orresilience of the material while withstanding recoil forces.

A corollary objective of the invention is to provide a substantiallyrigid rifle stock wherein material deformation during recoil andrecovery from recoil is entirely elastic so that no permanentdeformation or dislocation of the features and structures of the riflestock would occur from one shot to the next, or over the service life ofthe stock.

The above challenges and disadvantages in the current art are addressedby providing a hollow or at least partially hollow stock comprising arigid exterior shell, and installing therein a small, strong span madeof a carbon fiber composite, a metal or similar substantially rigidmaterial, structurally adhered to the shell before adding internalfiller material such as foam. The rifle stock is configured to receive abarreled action having a downward protrusion. The shell portion of thestock has opposed sidewalls extending from a bottom portion and anintermediate portion. The span element spans between the opposedsidewalls, and includes a structural element that connects to the shell,and also contributes a forward edge to a protrusion receptacle definedin part by fill material in the stock and in part by the span elementitself. The protrusion receptacle receives the downward extendingprotrusion of the rifle action. The fill may comprise rigid foam,composite materials, carbon fiber, or combinations of these materials.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a shows a right side view of a rifle which includes an embodimentof a reinforced rifle stock in accordance with the invention.

FIG. 1 b shows a top view of the rifle and stock of FIG. 1 , definingsection line A-A for the cross section view of FIG. 5 and section lineB-B for the cross section view of FIG. 6 .

FIG. 2 shows an embodiment of a reinforced rifle stock in accordancewith the invention with some components exploded for discussion.

FIG. 3 shows a top view of an embodiment of a span element for areinforced rifle stock in accordance with the invention.

FIG. 4 shows an oblique, top rear right side view of a barreled actionengaging with exploded components of a reinforced rifle stock inaccordance with the invention.

FIG. 5 shows a cross section view of the barreled action and reinforcedrifle stock of FIG. 1 , taken at section line A-A of FIG. 2 .

FIG. 6 shows a cross section view of the barreled action and reinforcedrifle stock of FIG. 1 , taken at section line B-B of FIG. 2 .

FIG. 7 a shows an intermediate portion of an embodiment of a reinforcedrifle stock in accordance with the invention having a span elementembedded in fill material within the shell of the stock.

FIG. 7 b shows the intermediate portion of the reinforced rifle stock ofFIG. 7 a without the hidden lines of the span element.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

Traditional composite stocks consist of a strong composite shell thatmakes up the exterior shape of the stock which is filled with an epoxyor foam fill that fills the interior of the shell. The fill is molded ormachined to accept the metallic components of the rifle. The molded orinletted portion is called the inlet. The recoil of the rifle isgenerated in the barreled action. The recoil impulse is transferred fromthe recoil lug of the action into the fill of the stock. The stock fillthen transfers the recoil impulse into the composite stock shell. Theshell of the stock then transfers this impulse to the recoil pad andthen into the shoulder of the shooter.

Because the fill has to transfer the recoil from the barreled action tothe composite shell, it has to be strong enough to withstand thisenergy. The fill also makes up the majority of the volume of a stock soits weight plays a major role in the overall weight of the stock.Selecting a fill material that is both extremely lightweight and yetstill strong enough to transfer the recoil impulse is difficult. Somecomposite rifle stocks have aluminum bonded or embedded into the fill tohelp transfer this load. The aluminum is much heavier than the fill orthe composite shell.

The present invention places a supporting shelf of lightweight compositematerial inside the fill that can interact with the recoil lug andtransfer the recoil impulse directly from the recoil lug to the shell ofthe stock. One possible method of attaching the recoil shelf onto thestock shell is to bond it on with epoxy. The recoil impulse would thenbe transferred from the shelf, through the epoxy bond, and into thestock shell. The action is spaced apart from the recoil shelf by thestock fill, except where the lug contacts the edge of the recoil shelf.By transferring the recoil impulse through the recoil shelf instead ofthe stock fill, less load is placed on the stock fill so the fill doesnot have to be as strong, and can be made of a much lighter weightmaterial.

Referring now to the figures, FIG. 1 a shows a right side view of arifle which includes an embodiment of a reinforced rifle stock [10] inaccordance with the invention. The rifle stock is configured to receivea barreled action [3] having an attached barrel [2.] The rifle stockcomprises a rigid exterior shell with internal reinforcements andoptional fill materials. The shell has opposed ends [4 a] and [4 c] andan intermediate portion [4 b] proximal to the barreled action of therifle. A typical length dimension [L] for the rifle stock may rangebetween about 18 to about 40 inches, an a typical height dimension [h]at the butt of the rifle stock may range between about 3¼ inches toabout 8 inches.

FIG. 1 b shows a top view of the rifle and stock of FIG. 1 , definingsection line A-A for the cross section view of FIG. 5 and section lineB-B for the cross section view of FIG. 6 .

FIG. 2 shows an embodiment of a reinforced rifle stock in accordancewith the invention with some components exploded for discussion. Thestock [1] is shown here without the butt plate and shoulder padcomponents and is preferably embodied as a hollow shell to reduce itsweight. The stock assembly includes pillars [6,7] for withstanding thecompression forces of threaded fasteners [8,9] which engage in threadedholes in the action or receiver of the rifle to secure the barreledaction to the stock. According to the invention, an additional componentvariously called a shelf, a span, a bridge, or a span element [15] isalso deposited into the hollow intermediate portion of the stock. Whenthe barreled action is installed into the stock, it mechanically couplesto the span so that the span contributes to supporting the action duringrecoil and contributes to transferring the recoil impulses from theaction directly to the rigid external shell of the stock.

FIG. 3 shows a top view of an embodiment of a span element [15] for areinforced rifle stock in accordance with the invention. The span has anaperture which in whole or in part defines a protrusion receptacle [18]for receiving a protrusion of the rifle's action as illustrated in otherfigures. The span has a first forward edge [19] at the protrusionreceptacle which may also include an arcuate or concave portion [20] forreceiving or for clearance of a portion of the pillar [7.] The span mayalso include a second forward facing edge [19′] or face which is notpart of the perimeter of a protrusion receptacle. Although in preferredembodiments the recoil lug is received within the aperture of the span,it is also within the scope of the invention for the span to abut andsupport the recoil leg at its second forward facing edge.

FIG. 4 shows an oblique, top rear right side view of a barreled actionengaging with exploded components of a reinforced rifle stock inaccordance with the invention. A component of the rifle action such as areceiver includes a lower surface [23] which has a downward protrusion[24] also called a recoil lug. One from among several threaded fastenersis shown threadably engageable to the rifle action. The fastener passesthrough the exterior shell of the stock and through a pillar [7]embedded or incorporated within the fill material of the stock. Thepillar may also be affixed to the shell of the stock and may alsooptionally include internal threads. The pillar avoids over-compressionof the fill material of the stock by preventing over-tightening of thefastener. When assembled, the recoil lug or protrusion is received in toa protrusion receptacle [18] of the span element [15] and abuts aforward facing edge or face of the protrusion receptacle. With theopposed sidewalls [16] of the span also securely affixed to interiorsurfaces of the shell of the stock, the span element stabilizes theaction and barrel during recoils.

FIG. 5 shows a cross section view of the barreled action [23] andreinforced rifle stock of FIG. 1 , taken at section line A-A of FIG. 1 b. During discharge of a cartridge, recoil force originates at the boltface and is opposed at the recoil lug. The tang or rear facing surfaceof the downward extending protrusion [24] inserts into the protrusionreceptacle defined at least in part by the aperture in the span element[15] which is seen in this view as a planar element. The forward edge[19] of the aperture in the span element abuts the recoil lug so thatthe span may accept a portion of the recoil impulse.

The shell [31] of the rifle stock may be formed of any suitable andsubstantially rigid material such as polyamide (Nylon®) which may acommon 6 polyamide or a cross-linked nylon such as a 4-6 or 6-6polyamide. Other suitable polymer and synthetic materials includepolypropylene, fiber infused resins such as a fiberglass and epoxycomposite material, or a composite comprising a carbon fiber material.Natural materials such as wood may also be used for the shell of a riflestock in accordance with the invention. A shell thickness [t] may rangebetween about 1/32^(th) of an inch to about ¾ of an inch.

The stock may be constructed as a hollow or partially hollow assembly inwhich the shell contains the span and the pillars only, but preferablyincludes a fill material [32] at least partly occupying the hollowinterior. If created by additive manufacturing, the interior of thestock may include trussworks or frameworks which may further compriselongitudinal or transverse beam elements, or comprise beam elementsaligned to withstand the recoil force in columnar loading. Similarly,the orientation of fibers in a composite material may be axially alignedwith the recoil stresses which the shell withstands during recoil. Also,the cross sectional density of the fiber or other substrates of thecomposite material may be increased in portions of the shell which carryhigher working or principal stresses. The fill material may be naturalor may be a rigid foam, and the interior of the stock may be partiallyfilled and partially hollow. The density of the foam may be controlledby void sizes, and the density may be varied such as being increased inthe vicinity where the span transfers recoil force to the shell.

FIG. 6 shows a cross section view of the barreled action [3] andreinforced rifle stock of FIG. 1 , taken at section line B-B of FIG. 1 b. The stock comprises a shell [31] having an interior and an exteriorsurface defining an exterior of the stock. The shell has a bottomportion [33] and opposed sidewalls [34] extending from the bottomportion. A span element [15] is at least in part encompassed by fillmaterial [32] and the span is connected to the shell. The span elementhas a transverse intermediate portion [17] and vertical endportions[16,] and extends between the opposed sidewalls [34,] andincludes a structural connection [35] to the shell. The gaps between theside walls of the span element and the internal walls of shell allowspace for epoxy or other adhesives. The downward extending protrusion[24] or recoil lug of the rifle action resides in the protrusionreceptacle of the stock assembly and extends below the planar portion ofthe span element. Although less preferred, the span element may also beattached to the interior of the shell of the stock by mechanicalfasteners.

FIG. 7 a shows an intermediate portion of an embodiment of a reinforcedrifle stock in accordance with the invention having a span element [15]or bridge embedded within fill material [32] within the shell [31] ofthe stock. The stock defines a protrusion receptacle configured toreceive the downward protrusion of the rifle action and the span atleast in part defines the protrusion receptacle. The span has a forwardedge at the protrusion receptacle for supporting the recoil lug. Theprotrusion receptacle may be defined in part by the fill material and inpart by the span element, or may be defined entirely by the aperture inthe span element if fill material is not present.

FIG. 7 b shows the intermediate portion of the reinforced rifle stock ofFIG. 7 a , but without the hidden lines of the span element shown. Thestock assembly provides a strong structure for resisting internalcompression so as to stabilize the receiver during recoil. The stock maybe assembled in steps, such as forming and providing a hollow stockcomprising a rigid material, and providing a strong span of metal orsimilar material to be structurally adhered to the interior of the shellbefore a foam fill is deposited within the interior of the shell. Theprotrusion receptacle may be machined into the fill and into a spanelement initially lacking an aperture in a single machining step.

In a preferred embodiment the recoil lug is coupled not to the foam butinstead abuts a shelf attached to the shell, which may even allowelimination of the foam entirely or the use of highly cancellousmaterial or truss-like structures as an internal structure designed totransfer recoil forces to the rigid exterior shell. The shelf may bedesigned to provide elastic compression during recoil, which is fullyrestored as it would be undesirable to allow plastic or permanentdeformation of the support components in the stock assembly.

In constructing the hollow shell for the stock, an embodiment mayutilize composite materials comprising unidirectional, bidirectional, ormultidirectional materials, and may include additional layers ofcomposite materials such as carbon fiber and resin or fiber glass, andmay include increasing a density of reinforcing fibers in the vicinitywhere recoil forces are more concentrated. Additionally, a compositematerial structure in accordance with the invention may align orconverge fiber portions of composite matrix to address localized highstress zones. In an alternative embodiment, foam or other fill materialmay not be required if other structures are substituted which adequatelysupport and preserve the exterior ergonomic shape of the shell of thestock.

Thus, although many exemplary embodiments are described above, it willbe appreciated that the invention is intended to cover all modificationsand equivalents within the scope of the following claims.

I claim:
 1. A rifle stock configured to receive a barreled action havingan attached barrel and a lower surface, and having a downwardprotrusion, the stock comprising a shell having an exterior surfacedefining an exterior of the stock and having an interior; the shellhaving a bottom portion and opposed sidewalls extending from the bottomportion; the shell having opposed ends and an intermediate portion; afill material at least partly occupying the interior, and a span elementat least in part encompassed by the fill and connected to the shell. 2.The rifle stock of claim 1, wherein the span element spans betweenopposed sidewalls.
 3. The rifle stock of claim 1, wherein the span has astructural connection to the shell.
 4. The rifle stock of claim 1,wherein the span is a planar element.
 5. The rifle stock of claim 1,wherein the span has a transverse intermediate portion and vertical endportions.
 6. The rifle stock of claim 1, wherein stock defines aprotrusion receptacle configured to receive the protrusion, and whereinthe span in part defines the protrusion receptacle.
 7. The rifle stockof claim 6, wherein the span has a forward edge at the protrusionreceptacle.
 8. The rifle stock of claim 6, wherein the protrusionreceptacle is defined in part by the fill material and in part by thespan element.
 9. The rifle stock of claim 1, wherein the fill is a rigidfoam.
 10. The rifle stock of claim 1, wherein the shell is formed of acomposite material.
 11. The rifle stock of claim 1, wherein the shell isformed of carbon fiber material.